Laws may be initiated in either the Congress, the House of Representatives or the Senate. For this example, we will track a bill introduced in the House of Representatives.

When a Representative has an idea for a new law, he/she becomes the sponsor of that bill and introduces it by giving it to the clerk of the House or by placing it in a box, called the hopper. The clerk assigns a legislative number to the bill, with H.R. as the designation for bills introduced in the House and S as the designation for bills introduced in the Senate. The Government Printing Office (GPO) then prints the bill and distributes copies to each representative.

Next the bill is assigned to a committee (the House has 22 standing committees, each with jurisdiction over bills in certain areas) by the Speaker of the House so that it can be studied.
The standing committee (or often a subcommittee) studies the bill and hears testimony from experts and people interested in the bill.
The committee then may release the bill with a recommendation to pass it, or revise the bill and release it, or lay it aside so that the House cannot vote on it. Releasing the bill is called reporting it out, while laying it aside is called tabling.

If the bill is released, it then goes on a calendar (a list of bills awaiting action). Here the House Rules Committee may call for the bill to be voted on quickly, limit the debate, or limit or prohibit amendments. Undisputed bills may be passed by unanimous consent, or by a two-thirds vote if members agree to suspend the rules.

The bill now goes to the floor of the House for consideration and begins with a complete reading of the bill ( sometimes this is the only reading). A third reading (title only) occurs after any amendments have been added. If the bill passes by simple majority (218 of 435), the bill moves to the Senate.

In order to be introduced in the Senate, a senator must be recognized as the presiding officer and announce the introduction of the bill. Sometimes, when a bill has passed in one house, it becomes known as an act; however, this term usually means a bill that has been passed by both houses and becomes law.

Just as in the House, the bill then is assigned to a committee. It is assigned to one of the Senate's 16 standing committees by the presiding officer. The Senate committee studies and either releases or tables the bill just like the House standing committee.

Once released, the bill goes to the Senate floor for consideration. Bills are voted on in the Senate based on the order they come from the committee; however, an urgent bill may be pushed ahead by leaders on the majority party. When the Senate considers the bill, they can vote on it indefinitely. When there is no more debate, the bill is voted on. A simple majority (51 of 100) passes the bill.

The bill now moves onto a conference committee, which is made up of members from each House. The committee works our any differences between the House and Senate versions of the bill. The revised bill is sent back to both houses for their final approval. Once approved, the bill is printed by the Government Printing Office (GPO) in a process called enrolling. The clerk from the introducing house certifies the final version.

The enrolled bill is now signed by the Speaker of the House and then the vice president. Finally, it is sent for presidential consideration. The president has ten days to sign or veto the enrolled bill. If the president vetoes the bill, it can still become a law if two-thirds of the Senate and two-thirds of the House then vote in favor of the bill.